1. Field of the Invention
The invention concerns a condensation nucleus counter with a heated saturation unit through which gas flows that is loaded with solid particles from a sampling section supplied by a supply line that has a porous saturation element, which heated saturation unit is supplied with working fluid from an attached reservoir, a condensation unit that is downstream of a saturation unit, as well as a particle counter that is downstream of the condensation unit.
2. The Prior Art
Units of the type mentioned are known, for example, from the German utility model 73 21 827 or also from U.S. Pat. No. 4,790,650 and are used for measuring or counting very small particles by their effect on the dispersion of light in a ray of light. But these effects are then not safely or easily verifiable and measurable in the event the solid particles have dimensions that are too small (typically less than 0.3 pm), which is the case especially, for example, for the solid particles in exhaust gas of combustion engines and specifically diesel engines, which are almost exclusively responsible for corresponding analyses of the harmfulness of these exhaust gases.
In order to now also be able to work with particle counters of the type mentioned for particle sizes below the safe or simple limits of detection. It has become known, for example, from the named publications, to enlarge the apparent diameter of the particulate material thereby, that a working fluid is permitted to condense onto their surface, as a result of which easy and safe counting is possible in the desired manner, which is representative for the type and number of the particulate material in the particle-loaded gas flow. Aside from the use of, for example, water or water vapor as working fluid, for the improvement or optimization of the condensing, various other working fluid are common or have been analyzed—for example, alcohols and the indicated analyses of the exhaust gases of combustion engines, preferably also butanol. But working fluids of this type are not without problems for many applications with respect to their composition or their chemical components, as a contamination connected with certain operating conditions of such measurement units (especially fluctuating pressure conditions, pressure pulses) could, up to now, not be precluded with certainty by using other measuring methods or device sections, and local measurement errors connected with such must be avoided at all costs.
It is the problem of the present invention to improve a measuring unit of the type described at the beginning in such a way that its use is possible in all areas of environmental conditions that usually occur without disadvantageously influencing the other measurement environment.